Electric incandescent lamp



Mar. 27, 1923.

EL ROHNEH ET AL.

ELECTRIC INCANDESCENT LAMP.

FILED DEC. I4, i921.

Mw' www@ Patented Mar. 27, 1923.

UNITED STATES 1,449,627 PATENT OFFICE.

EMIL ROHNER, OF RHEINECK, SWITZERLAND, AND EDOUARD SIMIC, OF VIENNA,

AUSTRIA.

ELECTRIC INCANDESCENT LAMP.

Application led December 14, 1921. Serial No4. 522,451.

VTo all whom tf/nay concern: i

Be it known that we, EMIL RoHNER, a citizen of the Republic ofSwitzerland, and EDOUARD SIMIo, a subject of the King of Servia, andresidents, respectively, of Rheineck, in the Canton of St. Gall,Switzerland, and of Vienna, in the Republic of Austria, have inventedcertain new and useful Improvements in Electric Incandescent `Lamps, ofwhich the following is a specification.

The electric incandescent lamps hitherto known most of all have thedrawback that as soon as the single ilament has been burnt out or brokenthey become completely valuelem and have'consequently to be replaced.

Now, it is the object of the present invention to overcome lsuchdrawback, the characteristic feature of our invention consisting in thatprovision is made of a second and independent incandescent filamentwhich, by the aid of a third contact, is adapted to be mounted in theknownelectric lamps irrespective of their form, size o power. Thus,

" if and when the ordinary filament has beeny burnt out or broken-, thesecond lament is brought into the electric circuit by'means of the saidthird contact so that the great advantage is gained that the lamp, eventhough the first ilament has been rendered useless, may be furtheremployed. i

In order that the invention may be clearly understood reference is madeto the accompanying drawings, in which: v Fig. .1 shows an elevation,partly in section, ofa first construction and arrangement of ourimproved electric incandescent lamp, and l Fig. 2 shows a similar viewof a modication. v Similar parts are designated by like referencesthroughout theviews and the specifi- Ycation.

In ordinary electric incandescent lamps of the form, for instance,illustrated in Fig. 1, the lamp body or glass-bulb a has centrallymounted therein a iilament support b of lass which, like the bulb, is ofthe well own construction and provided at the top and near the bottomwith a collar b and b respectively. These collars serve for theattachment therein, in star form, of a series of wires c having hookslat their outer ends to which the filament is secured in the usual4manner, that is, by attaching one end of the filament to one of the twoelectric contacts commonly provided and guiding it zigzagwise up anddown and over the said hooks in order finally to attach the other end ofthe filament t the second contact.

As already indicated our invention does not interfere with theconstructionand arrangement of ordinary electric incandescent lampsexcept that the collars b and b are preferably made of a larger size topermit the mounting therein of a second series of wires d. These wires dare also disposed in star form but made rather longer than thosedesignated by c. A second filament, indicated in dotted lines in Fig. 1,is similarly .secured upon the hooked ends 'of the wires d as thatdescribed with reference to the wires c and has one of its contactscommon with the first filament, the other end, however, being connectedto a third contact mounted in the lamp and severely-insulated from andin respectv of the aforesaid second contact. .There is thus a doublewinding of filament, namely an inner and an outer winding.

The arrangement of the three contacts is the following: I

vTwo of the three contacts remain of the disposition known in electriclamps of the type-commonly used, the positive contact 1 being located 1nthescrew-threaded sleeve c I by means of which the lamp is mounted, andthe negative and insulated contact 2 being located in the negativepole-carrying fitting g of the electric lamp. The third contact 3,connecting with a contact member L and the louter lament, is fittedclose to the said second contact but is insulated therefrom by means of`a strip -z ofinsulating materia both the contact member h and the strip'L' being mounted in a recess provided in the aforementioned fitting g.

It will thus be seen that, whereas in the ordinary electric lamps theinsulation of the 4 Assuming noW that the inner filament has beenrendered useless, the insulating strip 1 is Withdrawn from its recess inthe fitting g in order to bring into action the third and hithertoinsulated contact 3 with contact member lz, and consequently cause thelighting ofthe outer filament. Supposing, on the other hand, theelectric lamp from the beginning to be fitted without the insulatingdevice described, both filaments are simultaneously lighted. In suchcase and since the filaments are parallelly mounted, the intensity ofVthe electric current must of necessity be doubled.

This invention applies equally Well to electric incandescent lamps ofother shape, such as to a lamp of the kind illustrated in themodifica-tion, Fig. 2, in which the lilament p is of undulatory form andmounted on the filament support b by means of a series of wires csecured at the circumference of the collar b of said support. In thiscase, too, we make provision of a second filament g Which is arrangedparallel to the first filament and suspended from the collar b' by meansof another series of Wires c. The arrangement of the three contacts l,2, 3, and that of the insulating strip-i and contact member it issubstantially the same as hereinbefore described with reference to Fig.l. v

What We claim as novel and desire to secure by Letters Patent is In theherein-described electric incandescent lamp of the kind having twofilaments mounted therein, the combination, with a screw-threaded metalsleeve carrying the lamp and a lamp-socket attached to the sleeve andprovided with a recess, of a com mon contact located in the said sleeveand connecting with one end of each of the filaments, two other andseparate contacts fitted at' the face of the socket, and a switchdetachably mounted in the aforesaid recess and comprising a contactmember and an insulating member adapted to cover one or the other of theseparate two contacts.

In testimony whereof we have hereunto set our hands in the presence ofthe subscribing witnesses.'

EMIL ROHNER. EDOUARD SIMIC. Witnesses for Emil Rohner: Or'ro FRrrscH, G.W. CHILIN. Witnesses for Edouard Simic:

GUILLERMO PEGKER, HERMANN PFLUG..

